Fluid pressure operated gear shifter



July 2, 1940. P. M. CARTER FLUID PRESSURE OPERATED GEAR SHIFTER Filed Oct. 8, 1937 2 Sheets-Sheet l S EESQ II E 211w TO mnonusvs y 1940. P. M. CARTER 6,221

FLUID PRESSURE OPERATED GEAR SHIFTER Filed Oct. 8, 1937 2 Sheets-Sheet 2 Z174 W ATTORNEYS Patented July 2,1940

uurrsn STATES PATENT OFFICE amen , FLUID ranssmm ornna'rnn GEAR snm'rna Philip M. Carter, Detroit, Mich" assignor to Vaco Products, Inc.. Jersey City, N. J...a corporation of Delaware Application October 8, 1937, Serial No. 187,973 In Great Britain my 28, 1937 7 Claims. (Cl. 192-35) The present invention relates to new and use- The invention is particularly applicable to sysful improvements in fluid pressure operatedgear, tems utilizing pressure operated fluid motors and shifters, and more particularly to such mechavalve arrangements of the general type described anisms which are semi-automatic in their opin the specification of British Patent No. 457,068

oration, and in United States Patent No. 1,733,502. The

' Objects and advantages of the invention will control device may consist of a selector valve or be set forth in part hereinafter and in part switch which controls the vacuum applied to the will be obvious herei'rom, or may be learned by fluid-pressure motors from. the inlet manifold practice with the invention, the same being reof the engine.

10 alized and attained by means of the instru- A lever is provided on the steering column or mentalities and combinations pointed out in the in any other suitable position and is adapted acappended claims. cording to one embodiment of the invention to The lnvention'consists in the novel parts, conmove the control device to its neutral, reverse or structions, arrangements, combinations and imlow speed positions from any speed position or provements herein shown and described. to move it to its intermediate speed position from u The accompanying drawings, referred to herethe high speed position.

in and constituting a part hereof. illustrate one The control device is adapted to be latched in embodiment of the invention, and together with either its low or intermediate speed positions by the description, serve to explain the principles a latching or escapement mechanism comprisof the invention. ing a latch which is adapted to be released by 20 Of the drawings: the engagement of the clutch and a latch which Fig. 1 is a schematic ,view, partly in section, is adapted to be .released each time the gears of a typical and illustrative embodiment of the are shifted to their low or intermediate posiinvention as applied to a conventional type of tions. Thus if the lever is moved to its low speed automobile selective change speed gearing; and then to its high speed position the gears are Fig. 2 is a section taken on the line 2-2 01' caused to shift first to low speed, then to inter- Fig. 1; mediate speed and finally to high speed, the con- Flg. 3 is a section taken on the line 3-4 oftrol device moving to the next higher speed po- Fig. 1; and sition after the completion of each change of gear.

Fig. 4 is a vertical sectional view illustrating Intermediate speedis obtained from high speed 30 the construction of one of the shifting cylinders. by moving the lever while declutching.

The present invention has for its object the I! desired, the action of shifting into interprovision of a novel and improved semi-automatic mediate speed may be skipped after the selector fluid pressure operated means for shifting the has been moved so that this action would norgears of a conventional automobile transmission. mally occur, and this may be accomplished by A further object is the provision of a simple and moving the lever so as to release the intermedi- 35 relatively inexpensive gear shifter by which the ate speed latch which it may do owing to the gears may be shifted from a low speed to a high lost motion connection between the lever and the. speed ratio by clutch operation alone after an control device, thereby enabling the control deinitial manual setting of the controls, while at vice to move directly to its high gear position the same time the ope ator may select and shift after meshing the gears in low speed. The low into such other gear ratios as may be required speed latch may also be omitted, if desired, in

by the operating conditions at any particular Y which case it is necessary to hold the lever in its time. low speed position until the gears have actually As embodied, a control device is provided for been shifted into first or low speed. controlling the shifting of the gears, this de- The latch rod which is withdrawn by the envice being manually returnable to its low speed gagement of the clutch is adapted to engage low position and being biased so as to be resiliently and intermediate speed shoulders on the control moved to its high speed position under the condevice and the other latch is adapted to be withtrol of an escapement mechanism which is drawn from its shoulder by movement of the in- 50 jointly actuated by the clutch pedal and by a termediate speed shift rod; A further latch, transmission element such a a gear shift rod. which is adapted to be withdrawn directly when The control device may be manually movable to the lever is moved to its skip position, may be the positions for giving neutral, reverse and interprovided to hold the control device in its intermediate speeds. a mediate position.

, f mm- Assuming that the engine ofthe car is running' and the control and gears are in their neutral' positions, the driver ln order to drive oil, declutches and moves the lever to its high speed 5 position, the control device moving as far as its low speed position, where, it is retained'by the latch, and causing the gears to engage low speed. n the driver engaging the clutch the car moves on in low gear and at the same time the escape- 10 went latch is released allowing the control de-;

vice to move to its intermediate position where it is retained by the other latch.

On declutching again the intermediate gear is engaged and on engaging theclutch .the conl3 trol device moves to its high speed position. Fi-

nally to engage high. gear, the clutch pedal is again depressed (to declutch) and released.

When stopping the vehicle, the driver declutches and moves the lever with the control 20 device to the low speed position where the latter is retained by the latch. This causes the gears to change to low speed and'the cycle of operations is repeated. To change from high to intermediate gear, thelever is moved back to its 25 intermediate position where the control device is retained by the latch. 0n declutching the gears engage in the intermediate speed and, if the lever has been moved back to high speed position, the

control device subsequently moves 'back to its at) highspeed position. If desired, however, the driver may, before declutching, move the lever beyond the high speed position to its skip position. This will serve to move thecontrol device from low to high, skipping the intermediate position. This also en-. ables the change to low' gear to be omitted if the operator changes his mind.

The operation of declutching is caused toapply the vacuum to the selected change-speed motors 0 or to energize solenoids, when these are used, by

any suitable method as, for example, in that described in the specification of British .Patent 457,068 or "that described in United States Pat-'- entNo. 1,733,502. 5 It will be understood that the foregoing general description and the following detailed de-,

scription as'well, are exemplary and explanatory of the invention but" are not-restrictive thereof.

Referring'now in detail to the illustrative em- 50 bodiment of the invention shown in the accompanying' drawings, there is provided the usual selective gear transmission .IILwhich is adapted to transmit power at'different ratios from the automotive engine to the propellershaft (neither of which isshown) under control of the clutch pedal II, depression of which causes disengagement of the clutch. The illustrative embodiment is suctioneo'perated by suction derived from-the usual intake manifold of the engine to which is 50 connected the main suction line i2. The fluid' pressure operated gear shifting means comprise two cylinders l4 and IS in which are reciprocabiy mounted-pistons l 5 and Hon piston rods lifand I1, and these rods are slidable in'the sleeve like 5 end portions ofthe cylinder walls; Piston rod i5 is'connected at one end to the gear shifting fork rod 20 for first speed and reverse by means of the yoke 2|, while piston rod I1 is similarly connected to the gear shlfting fork rod 22 for 7o se'condspeed and third speed by. means of the yoke 23, Cylinders [4 and 18 are preferably mounted close'to each other in-parallel and may be supported upon the upper portion of the transmission case. Suitableinterlock means of conventional construction maybe provided for preventing movement of pistbn I and its associated shift rods 20 away from the neutral position shown except when the piston I1 and its associ- Y ated shift rod 22 are in neutral position, and vice versa. v 8.

Pistons II and I1 are moved to one end or the other or are returned to the central position of their respective" cylinders by the application of suction to one end or the other or to the center of their cylinders through the pipes 25, 23, 21,

'28, 29 or 30, and suction is selectively applied to these lines from the master line i2 through the master control valve 3| line 32 and selector valve 33, and valve 3| is opened when clutch pedal ii is depressed to disengage the clutch.

When suction is applied to one of the lines to 30, to move the piston 15 or II, air is admitted to the opposite side of the piston to facilitate its movement by automatic release valves such as those fully described and shown in the prior 20 patent to Linsley, No. 1,733,502. Each of these release valves comprises a valve plunger 35 having a reduced head 33 which is seated by spring 33 against the face of port 31 opening into one end, of the cylinder, and when unseated, connects a port 31 to the atmospheric port 33. Valve I plunger 35 is adapted to be unseated against the compression of spring 33 by suction applied to the pipe 40 which connects the rear face of the plunger with the opposite end 01'. the cylinder. 30

The selector valve is illustratively shown as a plate 42 slidable over the valve body 43 and retained thereon by side members. 44 and a cover plate 45. Slide plate 42 is provided with various ducts which in the various positions of the slide 5 serve to connect the main suction line 32 with the various individual suction lines 25 to 30. As shown, lines 25 to 30 terminate in ports 25 to 30" in the valve body 43, while line 32 is connected to port 32'. o In the position shown, corresponding to neutral, port 32' is connected with ports 23? and 30' by ducts and Si formed in the valve slide 42. By moving valve slide 42 to the right, reverse position is obtained andthen port 32 is connected 5.

with ports30' and 21' by ducts 52 and 53. In first speed position, with the valve slide 42 immediately to the left of the position shown, port 32' is connected with port 30' and 25' by ducts 54 and 53.. Second speed position, the nextone 5 to the left, connects port 32', with ports 26' and 23' byduct 56. Third speed position, at the extreme left, causes port 32' to be connected with ports 29 and 23' through ducts 51 and BI.

Means areprovided for moving the selector 55 valve slide 42 to its'vari'ous positions, and thesemeans comprise a selector control lever pivotallymounted at- 3! adjacent to the steering I I wheel column or some other convenient location. Lever 60 is. connected by push-pull wire control 5 63 with a-leve'r 64 pivotally mounted at 65. on the clutch housing. The ends of lever 34 are rounded and oneend bears against an end ofthe push rod 66, which is connected to one end of the valve slide 42. A tension spring 68 connected between 05 ,lugs 63 and 10, on theshifting cylinder and valve slide respectively, tends tomove the valve slide Means are provided for holding the selector valve in first speed position until the gears have been meshed in first speed and the clutch has been engaged, as well as for holding the selector valve in second speed position until the gears have been meshed in that speed and the clutch has been engaged, and these means cooperate with the means for resiliently urging the selector valve towards high speed position.

As embodied; detents 88 and 8| are mounted on the push rod 88 and are adapted to engage with latch bar 82 to hold push rod 88 and valve slide 42 againstmovement under the influence of spring 88. Latch bar 82 is resiliently retracted by spring 88 and upon disengagement of the clutch, is projected into the path of stops 88 and 8|. Latch bar 82 is connected to push pull wire 84 having its end slidably mounted in block 85,

and is adapted to be engaged and moved by a portion of the clutch pedal Other detent means are provided and are adapted to be released by movement of the gears into mesh. As embodied, a second speed position detent 88 and a third speed position detent 81 aremounted on the push rod 88. Detent 88 is adapted to be engaged by latch bar 88 which is slidably mounted in a support 88 and is resiliently urged into latching position by spring 88. It is retracted from this position by means of a wedge-shaped end 8| of piston rod l5 cooperating with the beveled face of slot 82 formed 8 in the latch bar 88. The third speed detent 81 is adapted to engage latch bar 84, which is slidably mounted in the support 85, is resiliently urged into latching position by spring 88 and is retracted from latching position by the bevel member 81 adapted to move into contact with the beveled face 88 as piston i1 moves to second speed position.

Latch 84 may also be withdrawn by moving the selector lever 88- to the position indicated by S2, in which position the lower end of lever 84 presses bar I88 against the compression of spring |8| so that its beveled end |88 engages the beveled face .|82 of the latch bar 84 and serves to retract the pin 84, thereby enabling the operator to skip second speed in normal shifting, or to cancel his previous preselection of second speed. That is, if an operator on approaching a hill moves the lever 88 from high speed position to second speed position, while travelling in high speed position, so that on declutching he would shift into second, and thereafter the operating conditions change so that second speed is not required, the selector valve may be moved back to high speed position by moving the selector lever 88 to S-2" position.

The operation of the described embodiment may be detailed as follows:

Assuming that the engine is running with the gear shifting parts in the position shown in Figure 1, and the driver wishes to start the vehicle: The operator moves the selector lever to position 3, causing a movement of the selector slide 42 to the left to first speed position, under the influence of spring 68 until detent 88 engages the end of latch bar 88. When the clutch H is depressed, valve 8| is opened to apply suction to line 82, latch bar 82 is projected into the path of detent 88 and also serves to prevent further movement. The suction is thereby applied through ducts 54 and 55 to lines 25 and 88 holding piston in neutral position and moving piston l5 to the left into first speed position, thereby causing a similar movement of the shift rod 28 to mesh the transmission gears in first speed ratio. When the gears are fully meshed, end 8| of piston rod l5 causes retraction of the latch bar 88 thereby releasing the push rod 88 at this end, but it isstill held against movement until the clutch is engaged which causes the retraction of latch bar 82 freeing detent 88 and allowing the selector slide 42 to move to its next or second speed position. The selector cannot move to third speed position as yet due to the deter? 81' which is engaged by the end of latch bar The operator may then shift into second speed by declutching, which positions latch 82 in the path of detent 8|,applies suction through valve 8| ,line 82, duct 88, lines 28 and 28 and thereby moves the piston l5 and shift rod 28 to neutral position, releasing the conventional transmission interlock, and thereafter moving piston II to the right into second speed position. In second speed position, beveled member 81 retracts latch bar 84 to release detent 81, and when the clutch pedal II is returned to engaged position, the latch bar 82 is retracted allowing the selector slide 42 to moveto third speed position.

When the operator next declutches, suction is applied through valve 8|, line 82, ducts 51 and 58, lines 28 and 28,.thereby causing the piston l1 and its shift rod 22 to move to third speed posi tion.

On stopping the vehicle, or at any other time, the operator may move the selector lever 88 to first speed position, thereby pushing the selector slide 42 to first speed position, and when he next declutches the suction applied through valves 8|, line 82, ducts 54 and 55, lines 25 and 88, first neutralizes piston l1 and its shift rod 22 and then moves the piston I5 and shift rod 28 to first speed position.

Reverse speed is obtained by declutching and moving the selector lever 88 to R position. This moves the selector valve slide 42 to reverse position (extreme right) and suction applied through valve 8|, line 82, ducts 52 and 58 and lines 21 and 88 neutralizes the piston l1 and shift rod 22 and then moves piston I5 and its shift rod 28 to the right to shift the gears into reverse.

During any movement of either of the pistons I5 or I! under the influence of suction, one of the automatic valves is operated to admit air to the opposite endof the cylinder, thereby facilitating movement of the piston.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantimes.

What I claim is:

1. In a gear shifter to be operated by differences in fluid pressure, a movable selector controlling the fluid pressure difference on the shifting means for various forward and reverse speeds, means for urging the selector to a high speed position, manually operable means to move the selector from said high speed position to any of its other positions and an escapement means for releasing the selector step by step from a low speed to a high speed position, said escapement means being operated in part by the'fluid pressure difference operated means.

2. In an automotive gear shifter for use with a selective gear transmission, the combination of fluid pressure difference operated means for shifting the gears, a selector controlling the fliuid pressure difference acting on the means, manual means for moving the selector, resilient means urging the selector towards a given position and an escapement permitting step by step movement of the selector, a portion of the escapement being controlled by operation of the fluid pressure difference operated means.

3. In a gear shifter to be operated by timerences in fluid pressure to be used in a vehicle having a clutch pedal, a movable selector controlling the fluid pressure difference acting on the shifting means for various forward and reverse speeds, means; for moving the selector step by step to a high speed position, means for reverselymoving the selector to a low speed position, one of said selector moving means being manually operated while the other is resiliently operated, and means interconnecting one of the selector moving means with the clutch operating means whereby movement of the selector is in part dependent upon the movement of the clutch pedal.

4. 'In a gear shifter to be operated by diflerences in fluid pressure, a movable selector controlling the fluid pressure difference acting on the shifting means for various forward and reverse speeds, means for normally urging the selector to a high speed position, manually operable means to move the selector away from the high speed'position to a low speed position and means for'releasing the selector step by step, said releasing means'being controlled in part by the shifting action of the fluid pressure difference operated means.

- 5. In a gear shifter to be operated by diiferences in fluid pressure, to be used in a vehicle having clutch operating means, a movable se-.

lector controlling the fluid pressure diiference acting on the shifting means for various forward and reverse speeds, means for urging the selector towards a high speed position, means for reversely moving the selector to a low speed position, latch means for preventing movement of the selector to the next higher speed position until the gears have been shifted into each speed, and manual means for operating the latch means to skip a shift ,into a particular gear ratio.

6. In a gear shifter to be operated by ,diflerences in fluid pressure, a movable selector controlling the fluid pressure diflerence acting on the shifting means for various forward and reverse speeds, means for resiliently moving the selector towards a high speed position, manual means for returning the selector to a low speed position, latch means for holding the selector against resilient movement in certain of its positions, means operated by the fluid pressure difference operated shifting means for releasing certain of said latches, and other means for releasing the others of said latches.

"7. In a gear shifter to be operated by differences in fluid pressure, a movable selector controlling the fluid pressure difference acting on I certain of said latches, and other means for releasing the others of said latches, said selector being manually movable to and from reverse speed position;

PHILIP M. CARTER. 

